How Can I Tell If Ich Is Gone Or Hasn't Happened

[mrbncal]

sorry too many windows open, posted in the wrong thread.

[Acro-Phobia]

Got a couple of questions guys.

I did some powerhead changes in my display tank which stirred up everything for a few days and made my fish a bit nervous. After about a week, my powder blue started showing signs of ich. Now, real bad.

Catching him will be a major feat, but if I am able to get him out of the display tank I can treat him. The problem is the tank. I had not seen ich in it for 6 months, but obviously it was there. Remaining residents are: 2 clowns, manderin, 6 line, and a lawnmower blenny. They are all healthy. Is there anything I can do to the tank short of catching everyone and going fishless for a couple of months?

[tmz]

Ich (crpytocaryon ) is in the confines of your system and will remain there unless you remove and treat all inhabitants with copper or hyposlainity and leave the tank fishless for several months.This protozoan is persistent. Some of the cysts can remain vialble for up to 72 days. Some of the fish may have parasites living on them unseen, perhaps in the gills.

I don't think any of the "reef safe cures" are worthwhile and are likely to intoduce more stress with reduced oxygen and some irritations from some of them.

Some relatively harmless and potentially beneficial half measures are:
UVsterilization with an oversized sterlizer at a relatively slow flow rate.This will be lethal to waterborn bacteria and algae including the dinoflagellate alga amyloodinium(aka the other ich or velvet).This dinoflagellate is almost always lethal unless treated early with copper or hyposalinity.Cryptocaryon is a protozoan a larger organism requiring higher doses of radiation to kill it.

Several RCers have recommended diatom filters to trap free swimming parasites.
Nutrition. A high quality variety of food perhaps enhanced with fresh garlic.
The obvious;water quality especially constant salinity,temperature and 0 amonia and nitite. Any thing you can do to reduce any stressors since the parasites, albeit in smaller numbers are ready to break out.
Good Luck

[Acro-Phobia]

Thanks Tom. I'm working on most of the items you mentioned already. I have never heard of a Diatom filter. Gotta look that one up.

[tmz]

Let me know what you learn about diatom filtration vs cryptocayon. You can never have too many good tools if it proves out.